Apparatus for handling molten metal



Jan. 25, 1938. K- S- HOWARD ET A'- 2,106,456

APPARATUS FOR HANDLING MOLTEN METAL Filed July 24, 1955 5 Sheets-Sheet lZ'A/ViA/TOES John Loce. /r/ .5. Howard.

Jan. 25,' 1938. K. s. HOWARD ET AL A'PPARATUS FOR HANDLING MOLTEN METALFiled July 24, 1935 5 Sheets-Sheet 2 /ar/ 5. Howard,

5V /7T7 EA/EY `Jan. 25, 1938. K 5 HOWARD ET AL 2,106,456

APPARATUS FOR HANDLING MOLTENk METAL Filed July 24, 19:55 5 sheets-sheets n 2z M H7* ENEY Jan. 25, 1938. K. 5 HOWARD Er AL 2,106,456

APPARATUS FOR HANDLING MOLTEN METAL Filed July 24, 1935 5 Sheets-Sheet 4Jan. 25, 1938. K. s. HOWARD ET AL 2,106,456

APPARATUS FOR HANDLING MOLTEN METAL Filed July 24, 1935 5 Sheets-Sheet 5Patented Jan. 25, 1938 UNITED STATES PATENT OFFICE APPARATUS FORHANDLING MOLTEN METAL vania Application July 24, 1935, Serial No. 32,922

7 Claims.

The invention relates to the art of melting, refining, and alloylngmetal, and consists in a novel apparatus for heating metal in a furnaceand pouring the metal from the furnace, and also consists in novelfeatures of the furnace structure.

The main objects of the invention are to facilitate the treatment ofmetals, particularly alloys, in a furnace, to eliminate the transfer ofmetal from the furnace to a pouring ladle, to combine electric and fuelheating means in a furnace, to arrange for the transportation of thefurnace to molds, and to control the flow of metal direct from thefurnace into successive mold openings.

Other detailed objects of the invention will be apparent from thefollowing description, reference being had to the accompanying drawingsin which- Figure 1 is an end view of a furnace mounted upon a supportingstructure including a weighing mechanism. Part of the furnace handlingmechanism is illustrated also.

Figure 2 is a rear view of the structure shown in Figure 1. y

Figure 3 is an end view corresponding generally to Figure 1 but showingthe parts in a different position.

Figure 4 is, in part, a top view of the furnace and, in part, ahorizontal section through the rear Wall thereof and a charging door.

Figure 5 is, in part, a front elevation and, in part, a longitudinalvertical section taken approximately on the line 5-5 of Figure 6.

Figure 6 is a vertic'al transverse section taken approximatelyon theline 6--6 of Figure 5.

Figure 6a diagrammatically illustrates the parts shown in Figure 6 whenthe furnace is tilted to a slag discharging position.

Figure 7 is a transverse vertical section taken approximately on theline 1-1 of Figure 2.

Figure 8 is an enlarged detail section of the Water connection to thestopper structure.

Figure 9 illustrates the means whereby a new discharge nozzle is appliedto the furnace from the outside of the furnace.

The furnace comprises a barrel-shaped body including an outer shell ofmetal I, lined with insulation 2, and an inner wall 3 of refractorybrick. Trunnions 4 and 5 project from each end of the body and may beengaged by suitable elements to support the body.

In Figures l, 2 and 5, trunnions 4 and 5 rest in brackets 6 and 1,respectively, carried on the upper end of an upright structure 8 mountedon a framework 9 of a weighing scale structure I0.

The furnace is stably supported upon the scale frame and the weight ofthe contents of the furnace and any additions thereto may be determinedreadily.

The ends 5a of trunnions 5 project outwardly beyond brackets I and maybe engaged by hooks II depending from an overhead traveling cranestructure I2 of ordinary construction. By raising hooks I I, the furnacemay be tilted in a clockwise direction about the axis of trunnions 4.When trunnions 5 are raised, brackets 'I may be turned on their pivotsto the dot and dash line shown, which permits the furnace to be tiltedanti-clockwise from the position indicated in Figures 1 and 6 to theposition indicated in Figure 6a. g

The front of the furnace is provided with a pair of charging doors I3for closing charging openings I4, and the rear of the furnace has adischarge opening fitted with a refractory nozzle I5 which is set in abed I6 of ramming mix. Discharge from the nozzle 'is controlled by astopper including a tip I1 and a composite tubular and refractory rodI8-I 9 whereby the tip of the stopper is held in nozzle closing positionby a stopper rig, indicated generally at R, and not constituting initself the present invention. A water inlet pipe 20 passes through asuitable bushing 2l in the outer end of tube I8 and extends to near theinner end of the tube from whence it is ,discharged and may flow throughthe tube to the outlet pipe 40 whereby circulation of cold water throughthe tube may be maintained while the furnace and its contents are beingheated. This counteracts the tendency of the heat in the furnace to warpthe rod and unseat the tip of the stopper from the nozzle.

The pouring nozzle has to be replaced after each heat and the setting ofthe same is so constructed that the nozzle can be removed and replacedfrom the exterior of the furnace, making it unnecessary to let thefurnace cool down between heats sufliciently to permit Workmen to enterthe furnace. By detaching the removable plate 22, nozzle I5 and its bedI6 may be knocked out. A new nozzle may be inserted and held in place bya centering rod 23 (Figure 9) extending through the furnace along theaxis of the stopper rod (which will be removed) and fresh nozzle bedmaterial in plastic condition rammed between the nozzle, the adjacentrefractories 3, and against a backstop 26. Rod 23 may then be removedand plate 22 replaced.

The furnace illustrated is of the induction heater type, including twosingle phase coils, although Gil any number of single phase coils couldbe used and the other features described could be embodied in any typeof electric furnace. Gas burners 25 dry and heat the furnace prior tothe functioning of the electric heaters and also supply additional heatduring the operation of the electric heaters, thereby reducing theamount of eltrical energy required for the furnace. The gas burners havesupply conduits 26 and 21 for gas and air, respectively, the same beingequipped with individual valves 28 and 29, respectively, whereby theproportions of gas and air passing through the burners may be controlledand the atmosphere in the furnace can be made either oxidizing orreducing. If, for example, ten parts of airto one part of gas would forma neutral combustion jet, increasing the proportion of air would form anoxidizing atmosphere in the furnace which would burn out carbon,manganese, silicon, etc., whereas cutting down on the proportion of airwould form a reducing atmosphere in the furnace resulting in adding theelements from the slag to the molten metal.

Each electric heating unit H includes a tube 30 for metal, it being aninherent characteristic in an induction furnace of this type that noheat can be obtained until metal is in the tubes surrounding the coils.The upper end of each tube 30 opens to the interior of the furnace abovethe face of the bottom wall whereby small residue of metal or slag leftin the furnace after a pouring operation will not drain into the tubesand solidify when the metal is cold. Also fragments of the refractory 3,or other debris, will not be so likely to fall into the tubes.

Operatio1t-t will be understood that the present furnace is notordinarily used as a melting unit, but it supplements such use forsuperheating or for changing the chemical composition of the steel. lThefurnace, stabilized as indicated in Figures l and 2, will be chargedusually with a quantity of Amolten metal M to which a suitable slagmaterial S will be added, the quantity of each portion of each chargebeing readily and accurately determined by use of the weighing mechanismupon which the furnace is mounted. After adequate heating, and othertreatment by means of the air and gas connections, the furnace will betilted to the position shown in Figure 6a to discharge the slag throughopenings M, after which the second slag producing material will be addedto the furnace and treated, and the contents of the furnace oxidized orreduced by controlling the air and gas conduits.

The air, gasl water and electric conduits will then be disconnected andthe furnace lifted bodily by hooks l and transported by the overheadcrane structure The lifting of the furnace automatically rotates it tothe pouring position shown in Figure 3 in which the discharge nozzle l5is at the lowermost level and the stopper rig R is in position to bemanipulated by men on the foundry or mill floor, or on suitableplatforms adjacent the molds into which the contents of the furnace isto be discharged.

When the furnace is suspended by hooks l I, as indicated in Figure 3,the molten metal tends to counterbalance the weight of the transformerof the heating units. When the furnace is rotated to the position shownin Figure 3, the latch 3l engages the lug 232 on the downwardlyextending portion of hook i5 and holds the furnace locked in the angularposition shown so that the furnace will not be tilted accidentally,particularly during pouring operations, and divert the stream of fluidfrom its intended path.

By manipulating the stopper, the fluid may be discharged intermittentlydirectly from the furnace into successive mold openings either in thesame mold or in different molds. The location of heating units H aboutthe circumference of the furnace body is such that with the furnace inpouring position, tubes 30 are inclined to the horizontal and any metaltherein will flow out of the tubes into the body of the furnace. 'I'hisavoids the tubes being filled with slag when the furnace is cold. Theslag being non-inductive would prevent the electric heat units fromfunctioning later.

The molten alloy remains in the closed furnace protected by its coveringof slag until the moment of discharge into the mold. There is no undueexposure to oxygen in the air or to cooling temperatures as would followtransfer of the metal from the furnace to a pouring ladle fortransporting the metal about the mill or foundry in the usual manner.Obviously, the handling and transporting of the metal is simplified andthe temperature of the metal conserved. The furnace may be charged forsuccessive heats and double slag operations with a minimum amount oflost time between pourings.

These and other advantages are attained by the general arrangement ofthe details described above, but it is not essential that each featuredescribed be included in the furnace if its particular function isconsidered unnecessary. Mostv of the details of construction arerelatively unimportant and may be varied substantially. The exclusiveuse of all modifications of the described structure coming within thescope of the appended claims is contemplated.

What is claimed is:

l. In a combined furnace and pouring ladle, an electric heating unit atone side of the furnace, a fuel burner at the other side of the furnace,and charging and discharging openings in the wall of said furnaceintermediate said unit and burner.

2. In a furnace of the class described, a metal containing body having abottom wall, a metal receiving tube with its upper ends normally openingupwardly into said body, said ends normally being above the lowermostportion of the inner face of said wall whereby material resting on saidportion will not enter said tube by gravity.

3. In a furnace of the class described, a body for containing moltenmetal, there beingv a discharge opening in front of said body, trunnionsprojecting from the ends of said body located near the rear of saidbody, heating members mounted on the rear of said body, and means for 'itilting said body on said trunnions to discharge molten metal throughsaid opening, said trunnions and members being constructed and arrangedso that when said body is tilted to discharge the molten metal thereinthrough said opening the mass of the metal tends to counter balance saidmembers.

4. In combination, base supports, a furnace having trunnions arranged toengage strut supports respectively to mount said furnace in stableposition, means for tilting said furnace from said position in onedirection about the trunnion on one of said supports, the other of saidsupports being movable out of the path of the corresponding trunnion toprovide for tilting of said furnace from said position in the oppositedirection.

5. In combination, a furnace having a plurality of externaltrunnion-like members at opposite ends, brackets for engaging saidmembers to supn port said furnace in stable position, means for tiltingsaid furnace on its trunnion on one of said brackets, the other of saidbrackets being rotatable to non-functioning position to accommodatetilting of said furnace.

6. In a metal refiningvfurnace a chamber for holding a liquid charge,tilting trunnions extending from said chamber to hold said chamber invarious angular positions and for tilting same, electric means forheating and stirring a charge in said furnace, fuel and air means forheating and controlling slag reactions in said furnace,l

means for admitting a charge to said furnace, and a controlled stopperedopening normally above the molten metal level in said furnace butrelatively near the lowest part when same is tilted to pour a charge.

7. In a'furnace, a barrel-like body, a plurality of trunnion-likeelements projecting longitudinally from the end of said body whereby thefurnace may be mounted upon external supports, atleast one of saidsupports being located eccentrically of the axis of said body wherebythe furnace may be tilted about the other element and a controlledstoppered discharge opening in the side wall normally above the level ofa straight line passing through said trunnion elements.

KARL s. HOWARD. JOHN H. LOCKE.

